1. Field of the Invention
The present invention relates generally to a gas laser device for use in machining, and more particularly, to a gas laser device having a main unit including a power supply, and a laser beam emitter separate from the main unit.
2. Description of the Related Art
Gas laser devices are widely used for cutting and welding metal. Two typical gas laser devices are shown in FIGS. 9 and 10.
FIG. 9 shows a high-speed axial-flow-type gas laser device which includes a laser beam, 61 resonator reflecting mirrors, 62a and 62b a discharge tube, 64a, 64b heat exchangers 64a and 64b for absorbing heat of the discharge gas and discharging the same to cool the gas, an air blower 65 for circulating a laser medium gas, and a DC high-voltage power supply 66 for generating electric discharges in the discharge tube.
In this type of gas laser device, electric discharges are produced in the discharge tube 63 to excite the laser medium gas which flows at a high speed in the tube for thereby causing laser excitation.
FIG. 10 shows an orthogonal-type gas laser device. Those parts which are identical to those shown in FIG. 9 are denoted by identical reference numerals, and will not be described in detail. Discharge electrodes 67a and 67b disposed in an opposing relation to each other.
In this type of gas laser device, electric discharges are generated between the electrodes 67a and 67b to excite a laser medium gas flowing at a high speed between the electrodes for laser excitation.
In order to operate a gas laser device efficiently on a continued basis, the temperature of the gas in a discharging unit must be kept low. Both of the above gas laser device types are equipped with a heat exchanger and an air blower, and a discharging power supply of a substantial size, and hence have a substantial weight and volume as a whole.
Systems for machining workpieces using the above laser devices include a system in which the workpiece is moved and a system in which a laser beam is scanned. In the system in which the workpiece is moved, a machining table is large in size, the machining speed is low, and three-dimensional machining is especially difficult to achieve. Therefore, the system in which the laser beam is scanned and a system in which the workpiece is moved and the laser beam is scanned are mainly relied upon at present.
When the laser beam is scanned, however, the optical distance between the laser device and the workpiece is varied, resulting in lowered machining performance.